With the rapid development in science and technology, more and more portable electronic devices such as mobile phones, digital cameras, tablet computers, and notebook computers or the like have become essential tools in people's lives. Since portable electronic devices are generally used by individuals and have certain privacy, data stored inside the electronic devices (such as phone books, photos, personal information) is privately owned. Once the electronic device is lost, the data may be used by others, causing unnecessary losses. Although password protection has been used to prevent the electronic device from being used by others, passwords may be easily leaked or cracked, thus having a low degree of security. Moreover, the user has to remember the passwords so that the electronic device can be used. If the passwords are forgotten, a lot of inconveniences are brought to the user. Therefore, a personal fingerprint identification system has been developed for the purpose of identity verification so as to improve data security.
For a fingerprint identification system, a square wave signal having a high-voltage amplitude is used to enhance the fingerprint signal. However, in order to generate the high-voltage square wave signal, a semiconductor component having a high breakdown voltage is produced by using a high-voltage semiconductor process, and a signal generation circuit thereof is formed by using the semiconductor component having a high breakdown voltage. However, the high-voltage semiconductor process involves high production cost, which leads to an increase in the production cost of the electronic products of a circuit system for fingerprint identification.
Therefore, how to use a semiconductor component manufactured by using a low-voltage process to generate a square wave with a high-voltage amplitude is one of the goals to be achieved in the industry.